The Food and Drug Administration has wrapped up three days of hearings and public comment on the effort by AquaBounty Technologies, a Massachusetts company, to sell salmon genetically engineered to grow twice as fast as normal salmon. But the meetings ended without an FDA decision on whether the company can move ahead with sales. USA TODAY's Elizabeth Weise [answers questions about the issue]: Q: What are the issues? A: There are really two: Are these fish safe to eat, and are they safe for the environment? FDA staff, in a report released earlier this month, found the genetically engineered (or GE) salmon to be as safe to eat as normal salmon. But several members of the agency's Veterinary Medicine Advisory Committee felt that the tests for food safety could have included more data and encouraged the agency to request more from the company. Q: What's the environmental issue? A: Some scientists and environmental groups worry that if these fast-growing salmon escaped into the ocean, they might out-compete native salmon populations for both food and mates. As almost all wild Atlantic salmon are endangered, anything that could harm them is of concern.